[djmtsu]

My FC is a amazingly quiet with the set up I have now. But I am worried I am taking a loss on performance.

I would use the XR-1, a friend of mine has one as a silencer on his turbo 6 port with an RB catback. It makes it sound a little odd, but that might be because of the RB system. I might see if we can put it on mine and see how it goes.